1. Field of the Invention
The present invention relates generally to a wafer probing machine, and more particularly to a wafer probing machine that measures and tests electric characteristics of integrated circuits formed on a semiconductor wafer.
2. Description of Related Art
The wafer probing machine has a wafer cassette containing wafers subject for probe, an inspection tray on which a wafer for inspection is placed, and a special tray on which a cleaning wafer for cleaning probe needles is placed.
In a conventional wafer probing machine, only the inspection tray can be drawn out from the body of the machine, whereas the special tray cannot be drawn out since it is fixed in the body of the machine. Hence, in order to find what type of cleaning wafer is currently placed on the special tray, the operator must pick up the cleaning wafer from the special tray by means of a transport arm that is provided in the body of the machine.
It takes a long period of time and is very inconvenient to pick up the cleaning wafer by means of the transport arm. Moreover, since the transport arm is also used for transporting the wafers between the cassette and a probe part, the machine must be suspended when the cleaning wafer is picked up while the machine is working, and thus, the throughput is decreased.
The present invention has been developed in view of the above-described circumstances, and has as its object the provision of a wafer probing machine that makes it possible for an operator to easily confirm types of wafer placed on a wafer tray.
To achieve the above-mentioned object, a wafer probing machine of the present invention is characterized in that a plurality of wafer trays are stacked in a body of the wafer probing machine and are capable of being drawn out from the body.
According to the present invention, the operator can easily confirm types of wafer that is placed on the wafer tray by drawing out the stacked wafer trays from the body of the probing machine even while the machine is working. Since at least one of the wafer trays is detachable from the other wafer trays, the wafer that is placed on the detachable wafer tray can be easily transported to another place.